smason

It was not logging. Engine builder says it melted a piston and the motor had signs of major detonation. Apparently both the shop that sold me the motor, and the tuning shop are both sketchy people.

Well its been a sad week. After getting my car tuned (1JZGTE), some of my first high gear high boost pulls blew the motor. I was wondering if there was any way to see the data of the final moments of my beloved JZ. Whether oil pressure tanked or it over boosted etc...

Yeah mine is upwards of 4.034 or something on a Nissan S13

Well I have an update! I've been working almost non stop so I've been very busy. But this will be the finale - I think. I have just been driving with the tachometer which is less twitchy, and no speedometer. Well as legend has it, last night I was driving to work, and the speedometer came to life! I changed nothing. I did nothing. The RC circuit works and it is kind of accurate. The multiplier works but the speedo is just 'out' at higher speeds. No fault of the G4. This is a classic representation of a USDM 240sx and it's troubles.

The VSS did not fix the speedometer. I built that RC circuit fine. Trying to find a friend with an oscilloscope.

I have a new tach, and it sort of works. Is accurate with a .93ish multiplier, but it randomly pegs. Looks like it's just an issue with the cluster. Now to find a good tachometer. Note for future USDM 240SX S13 cars. : YOU MUST USE A DOHC TACH. Speedometer is the same between the two. Waiting on the vss, should be here today. Then we'll see if that's working or not. Common issue with s13 clusters.

I took the tacho right out of the cluster, gave it +12v , GND, and Aux 1 as tach/ pwm. No luck on either. Trying to find a 3rd gauge cluster.

I've shut them all off, noticed 4-6 had some sort of limitation. I've pulled the tacho right out to eliminate harness issues. Fed direct power and Aux 1 set to tacho. Still not working. I'm going to try and borrow an additional tach from a friend but who knows.

So after lots of research, I hardwired the output of the ECU directly to the tach. It still doesn't work. I am seeing a DC voltage (6v) on this wire. Does that make sense?

Im just compiling all the info i can find online here. Sorry for the spam. The DOHC tach gets a 0-5V signal from the ECU and the SOHC tach gets a 0-12V signal off the coil.

Found this: "The dohc tach and sohc tach work completely different. The sohc works on a pulse single just like an autometer tach. the dohc tach works on a voltage scale."

I was checking run time values and i see this. Does this have something to do with it?

Spoke too soon. Something is still wrong. Speedo does not work and tach is stuck at 7k. Im using aux 5 and 6. Is there any issues with that?

So after lots of research, it appears that there is a difference internally from the SOHC to DOHC versions of the car, mine is an 89 with single slammer, I swapped the dash over to a DOHC, and it seems to be functional. Whether that was my specific unit or a actual incompatibility I am not sure. Now to tune the multiplier. And the tach jumps around alot. Not very smooth. Any advice?

Hm. Ill test that shortly. Neither speedo or tacho are working. I think my VSS might be bad, is there a way to simulate an output to check my speedometer? The cap/resistor circuit makes a sin wave across 0v, so if i send a DC voltage it should work, no? Found this: He was trying to get his cruise working.

No dice on either. It seems as though there is an issue with the cluster maybe. Is there any way i can be sure the ecu is outputting the signal? Voltage or resistance? In other news, I drove the car on the base tune for the first time. Wow. That was way faster than the car ever was on the stock ecu. Like crazy. I just wish the gauges worked now. Side Note. My oil pressure was 6psi lower than normal. Has anyone seen this? Additionally, What would the Key sweep occur on? Ignition power? or Start signal? I have my Ignition input on low activation because the entire harness is on switched power. The DI i have is for start signal.

Mine was a 1989 with KA24E and it was a single coil (igniter) and distributor iirc. Trying the speedo settings now.

Okay so Ive found a few more issues around the creature comforts. Speed and Tacho. The car runs and now waiting for some dyno time. Ive created the cap/resistor circuit for speedo output, and wired the tacho to Aux 6 and 5 respectively. Ive tried to turn this on and it seems not to work. Ive got key sweep on and i dont get anything on the dash. The car is a S13 240sx. I believe this is user error and would like some guidance. Ive set the Auxilary outputs, yet when looking at runtime values, they show as off. Any ideas? Not sure about sweep freq yet..

Just thought I'd update, there seems to be an issue with the ign driver as pin A10 is outputting 5v constantly. Not sure why, although it still manages to fire the coil. Car is running, now to button things up..

Perfect, I was missing the screw on part which is why I couldn't ID it. Ordered. I've connected the Chase Bays harness and it seems to not be as "plug and play" as I'd hoped. It looks like I am getting constant power to my coils. I figure this should be on switched power instead. The blue light always stays on. Should this not be the case? Or is there a programmable input for the switched power? Thanks

Could you be so kind as to clarify, do you mean the factory ABS sensor? I heard something about it hitting a 500Hz limit

Cap ordered, For the R154 VSS, would my best option be the Marlin Crawler VSS unit, or could i use the existing sensor?

Looks like there is 3 wires. Ill be sure to use the 0-5v. Thanks! For the 1uF cap, is there a voltage rating i should be looking at? I found a 12v off Digikey that should work. Thanks for the info in such a timely manner!

Hi All, I recently picked up a Link G4+ Xtreme + Full Harness, And ive got some questions. Car is a 89 240sx with Non vvti 1JZGTE + R154 For the O2 sensor, I have a glowshift wideband that has a 0-1v analog output that I use for the factory 4 row ECU. Is this okay to run to the G4? I would like my Speedo and Tacho to work. I understand the G4 can do a tach output, What about speed? I think i am missing the r154 VSS but i could get one if thats required. Aside from changing the Supra base map trigger to 355, is there anything else I need to do to the MAP? I plan on driving the car to a tuning shop down the road. Im very hopeful this fixes my issues. This engine has been significantly down on power and misfires at low RPM with the factrory ecu. Thanks!